OKLAHOMA CITY, Okla. – From “A League Of Their Own” – It’s supposed to be hard. If it wasn’t hard, everyone would do it. The hard is what makes it great.

If Oklahoma is to be considered one of the greatest college softball teams in history, it needs to win a national championship. The Sooners gained one of the two victories needed by overcoming an unthinkable degree of difficulty with one of the most incredible comebacks ever accomplished on any diamond.

Sooner Magic, they call it. And you would need Houdini, Harry Potter and the Witches of Eastwick to conjure a more mystical turn of events. It required nearly four hours of outstanding pitching, nail-biting drama and clutch hitting for Oklahoma to snatch victory from the snapping jaws of defeat.

Game One of the Women’s College World Series ended when sophomore Lauren Chamberlain pounded a two-run, first-pitch home run just inside the left-field foul pole. That gave the Sooners a walk-off 5-3 victory over Tennessee in 12 innings Monday night. Game Two will be at 7 p.m. Tuesday (ESPN).

“The best game I've ever been a part of,” OU coach Patty Gasso said.

Those who watched all 368 pitches most likely would agree. What led to Chamberlain’s walk off – her 30th of the year, tying her career-high and Big 12 single-season record – is the stuff of legend.

“That was one of the most amazing comebacks I've ever seen,” Gasso said. “I can't imagine. I mean, it's nervous on the field, I can't imagine how people felt watching it. To see how this all transpired is something that right now I can't remember, but I will never forget, if that makes sense.”

It makes as much sense as eight runs and 10 hits in one and a half innings after no runs and five hits in the previous innings.

Oklahoma trailed 3-0 going to the bottom of the 11th after Tennessee’s Madison Shipman broke up a scoreless pitcher’s duel with a line drive three-run homer to center field.

The Sooners were down to their last two outs when Keilani Ricketts lifted a skyscraper fly to the right side of the infield. Vols’ second baseman Lauren Gibson dropped the wind-blown chance (Ricketts wound up on second and was credited with a double).

Then Brittany Williams doubled home Ricketts. With two outs, Destinee Martinez tripled home Williams to make it 3-2. Martinez scored to tie it on Callie Parsons’ double to left center. Martinez and Parsons were both down to their final strikes.

“I think it was nerve‑racking and the nerves were there because this is the championship series,” Chamberlain said. “It's supposed to be like that in a game like that.”

And just like that, it was 3-3 and the 12th inning. Tennessee had never played a game longer than 11 innings in its history. The Sooners made sure it didn’t last longer than 12.

Brittany Turang led off with a chopped grounder just over third and blazed into second with a double. With first base open, it didn’t make a lot of sense to pitch to Chamberlain, the nation’s top home run hitter.

“We did consider walking her,” Tennessee co-coach Ralph Weekly said. “We felt like we could get her out, but obviously we were wrong.”

Chamberlain’s drive was drilled with such force it overcame any hooking tendencies and stayed fair.

“On my way to first, I was watching to see if it was foul or fair, and I was praying that it was fair,” Chamberlain said. “As soon as I saw it was fair and just seeing the crowd’s reaction and my teammates going nuts at home, I really couldn't believe it. It was awesome.”

The emotion displayed by the Sooners and their fans was as much relief as elation. Bitter would not have described the feeling had Oklahoma lost Game One.

In the third inning, Chamberlain roped a two-out double to the wall in left center. Turang was motoring around third when Gasso threw up the stop sign as the throw from the outfield reached Shipman. Instead of a play at the plate that could have resulted in a 1-0 lead, Oklahoma wound up not scoring.

After Tennessee starter Ellen Renfroe had retired 13 in a row, Oklahoma’s Georgia Casey opened the ninth with a single. An error, a wild pitch and a walk loaded the bases with one out but Jessica Shults grounded into a fielder’s choice with Casey out at home and then Martinez struck out.

For a team averaging eight runs per game, not cashing in on scoring chances while being shut out for 10 innings was like life in a parallel universe; the Sooners often didn’t go 10 at bats without scoring.

Ricketts had allowed one hit through 11.1 innings before a swinging bunt single and a line drive to center that Martinez nearly caught put two runners on for Shipman. Her 11th homer of the year and the three runs appeared to be more than enough for Renfroe, who had baffled the Sooners by mixing her fast ball and changeup.

But more than 10 innings of shutting out the Sooners – who had scored more runs (82) in eight NCAA games than their opponents had scored all season (71) – was too big a challenge. The sixth time through the Oklahoma batting order was one time too many.

“There is no break in the Oklahoma lineup,” said Renfroe, who struck out 13 and threw 180 pitches. “Every single pitch, it's all you've got. If you don't give everything, then it's going to get hit out, something bad is going to happen.”

Ricketts, who followed up allowing four hits in the top of the 11th with a 1-2-3 top of the 12th, fired 188 pitches in a career-long 12-inning outing. The two-time national player of the year was asked if she would be ready to throw Tuesday.